Wire Perl tree-sitter grammar

[konard]

Fixes #70

Summary

• Upgrade the tree-sitter frontend to the 0.26 line and add tree-sitter-perl 1.1.2.
• Wire Perl/pl through the built-in tree-sitter adapter and add Perl to the second-tier target and fixture registry.
• Update the parity roadmap, add a minor changelog fragment, and remove the automation .gitkeep placeholder.

Reproduction / Verification

• Before the fix, cargo test --test unit second_tier_programming failed because Perl was absent from the second-tier targets and perl parsed through the plain-text fallback.
• Added coverage for the Perl fixture, aliases, and recoverable malformed-source diagnostics.

Local Checks

• cargo fmt --check
• cargo build --all-features
• cargo clippy --all-targets --all-features
• cargo test --test unit second_tier_programming
• cargo test --all-features (184 unit tests + 3 doc tests)
• rust-script scripts/check-no-src-tests.rs
• rust-script scripts/check-file-size.rs (passes; existing warning-level near-limit files remain)
• rust-script scripts/check-crate-size.rs
• rust-script scripts/check-changelog-fragment.rs

Screenshots are not applicable; this PR has no UI changes.

[konard]

Working session summary

Implemented and pushed the fix to issue-70-c200ba7ef52d.

PR #82 is updated, marked ready, and CI is green: #82

What changed:

• Upgraded tree-sitter to the 0.26 line and added tree-sitter-perl.
• Wired Perl / pl through the built-in parser adapter.
• Added Perl to second-tier targets, fixtures, docs, tests, and changelog.
• Removed the PR automation .gitkeep placeholder.

Verification:

• cargo fmt --check
• cargo build --all-features
• cargo clippy --all-targets --all-features
• cargo test --test unit second_tier_programming
• cargo test --all-features
• rust-script guard checks, including changelog and crate size

Latest GitHub Actions run passed for commit 16cd1e7. Working tree is clean.

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This summary was automatically extracted from the AI working session output.

[konard]

🤖 Solution Draft Log

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💰 Cost estimation:

• Model: GPT-5.5
• Provider: OpenAI
• Public pricing estimate: $11.163753

📊 Context and tokens usage:

• 184.0K / 1.1M (18%) input tokens, 25.9K / 128K (20%) output tokens

Total: (184.0K + 8.2M cached) input tokens, 25.9K output tokens, $11.163753 cost

🤖 Models used:

• Tool: OpenAI Codex
• Requested: gpt-5.5
• Model: GPT-5.5 (gpt-5.5)

📎 Log file uploaded as Repository (35944KB)

• View complete solution draft log

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[konard]

🎉 Auto-merged

This pull request has been automatically merged by hive-mind.

• All CI checks have passed

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Auto-merged by hive-mind with --auto-merge flag